1. Field of the Invention
This invention relates to communication links and, more particularly, to communication over bidirectional links.
2. Description of the Related Art
Many systems employ conventional high-speed bidirectional signaling schemes in which the work of controlling amplitude and phase of the signals sent over a channel may be divided equally between each end of a communication link. In such systems, the control of the link may be symmetric such that the transmitter and the receiver at each end of the link may include very similar functionality.
An example of such a system may be a memory system, where there may be a complex master device (e.g., memory controller) and simpler slave devices (e.g., memory devices). The bidirectional data transfers would correspond to write data when transferring to the slave and read data when transferring from the slave.
At high data rates there may be cases where pathologically bad data patterns may be transmitted causing large numbers of bit errors. In addition, crosstalk may be a source of bit errors. Crosstalk can be generated by coupling between parallel conductors on a PCB, coupling in via arrays, connectors, packages, sockets, or in the case of a single ended switching system, as a result of multiple outputs switching simultaneously. Thus, it may be desirable to reduce the effects of crosstalk and to reduce the probability of generating pathologically bad data patterns.